Emissive transition-metal complexes with both carbon-phosphorus ancillary and chromophoric chelates, synthetic method of preparing the same and phosphorescent organic light emitting diode thereof

ABSTRACT

The present invention discloses a phosphorescent tris-chelated transition metal complex comprising i) two identical carbon-nitrogen (C^N) or nitrogen-nitrogen (N^N) chromophoric ligands being incorporated into a coordination sphere thereof with a transition metal, and one carbon-phosphorus (C^P) chelate being incorporated into the coordination sphere; or ii) one carbon-nitrogen (C^N) or nitrogen-nitrogen (N^N) chromophoric ligand forming a coordination sphere thereof with a transition metal, and two identical carbon-phosphorus (C^P) chelates being incorporated into the coordination sphere, wherein the metal is iridium, platinum, osmium or ruthenium, and the chromophoric ligands possess a relatively lower energy gap in comparison with that of the non-chromophoric chelate, the latter afforded an effective barrier for inhibiting the ligand-to-ligand charge transfer process, so that bright phosphorescence can be observed. The architecture and energy gap of the present molecular designs are suitable for generation of high efficiency blue, green and even red emissions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of U.S. application Ser. No.12/000,035, filed Dec. 7, 2007, which claims the benefit of U.S.Provisional Application No. 60/877,603, filed on Dec. 29, 2006. Thedisclosures of U.S. application Ser. No. 12/000,035, and U.S.Provisional Application No. 60/877,603 are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to iridium complexes, and moreparticularly to the phosphorescent iridium complexes with bothcarbon-phosphorus ancillary chelate(s) and chromophoric ligand(s),synthetic method of preparing the same and phosphorescent organic lightemitting diode thereof.

Background of the Invention

Phosphorescent organic light emitting diodes (OLEDs) are under intensiveinvestigation because of their potential of achieving improved devicebrightness and performances. In contrast to the fluorescent emission,the electrophosphorescence of heavy transition-metal complexes areeasily generated from both singlet and triplet excited states and, thus,the internal quantum efficiency can reach a theoretical level of unity,rather than the 25% inherent upper limit imposed by the formation ofsinglet excitons for the respective fluorescent counterparts. Thus, agreat deal of effort has been spent on the second and third-rowtransition metal complexes, for developing highly efficient phosphorsthat can emit all three primary colors.

US 2008-0161568 A1 discloses a phosphorescent tris-chelated transitionmetal complex comprising i) two identical non-conjugated cyclometalatedligands being incorporated into a coordination sphere thereof with atransition metal, and one ligated chromophore being incorporated intothe coordination sphere; or ii) one non-conjugated cyclometalated ligandforming a coordination sphere thereof with a transition metal, and twoligated chromophores being incorporated into the coordination sphere,wherein the metal is iridium, platinum, osmium or ruthenium, and theligated chromophore possesses a relatively lower energy gap incomparison with that of the non-conjugated cyclometalated ligand, thelatter afforded an effective barrier for inhibiting the ligand-to-ligandcharge transfer process, so that a subsequent radiative decay from anexcited state of these transition complexes will be confined to theligated chromophore. The architecture and energy gap of the ligatedchromophore are suitable for generation of high efficiency blue, greenand even red emissions.

SUMMARY OF THE INVENTION

The present invention provides the phosphorescent metal complexes withboth carbon-phosphorus (C^P) ancillary chelate(s) and chromophoricligand(s), synthetic method of preparing the same and phosphorescentorganic light emitting diode thereof for blocking the occurrence ofunwanted ligand-to-ligand charge transfer (LLCT) processes and possibly,giving an enhanced quantum yield for emission across the whole visiblespectral region. Definition of chromophoric ligands follows that of thetraditional concepts, namely: a chromophoric ligand is part of a metalchelate responsible for its visible color and/or respective emission.Moreover, when a metal complex with at least one chromophoric ligandabsorbs certain kind of energy from light source or electrical powersupply, thus energy can be converted by exciting an electron from itsground state into an excited state, for which the frontier orbitals areprincipally localized in the region of chromophoric ligand(s) of thephosphorescent metal complexes. Typical chromophoric ligands comprise ofaromatic, polyaromatic, or heterocyclic molecules that possess extensive1-conjugation over the whole chelating ligand.

The chromophoric ligands utilized in the present study can be classifiedto two kinds. The first class is denoted as (C^N)H, which comprise anitrogen donor segment such as pyridine, isoqunioline and quinazoline aswell as an aromatic or functionalized aromatic moiety that can reactwith the metal reagent via direct C—H activation, giving the so-calledcyclometalated chelates. The second class is subsequently named as(N^N)H chelate, which possesses the neutral N-donor segment plus asecond fragment with a N—H functional group, the latter can react withcentral metal ion in a fashion similar to the C—H activation occurredfor the (C^N)H chelate, giving formation of an anionic (N^N) chelateinteraction. Examples of these chromophoric ligands upon coordination tothe metal center are listed below:

(C^N)H Chelates

(N^N)H Chelates

On the other hand, the carbon-phosphorus (C^P) chelate mentioned in thepresent invention can serve as “electronic blocker” due to the saturatednature of phosphine fragment and thus, represents another class of“non-conjugated” ancillary chelate. It is notable that both the covalentmetal-carbon σ-interaction of the cyclometalated fragment and theπ-accepting character of phosphine donor is expected to strengthen themetal-chelate bonding interaction and destabilizing the metal-centereddd excited states. Population of metal-centered dd excited states willbe accompanied by elongation and severe distortion of metal-ligandbonds, promoting non-radiative decay to the ground state at theisoenergetic crossing point of the potential energy surfaces. Even ifemissive excited states of different character, such as MLCT orligand-centered ππ* states, lie at lower energies than the dd states,the latter can still exert a deleterious influence if they are thermallyaccessible. Thus, after lifting the dd excited state, the resultingmetal complexes are expected to exhibit enhanced chemical stabilities,more balanced electrochemical and enhanced emission efficiency at roomtemperature. Beside, the saturated bonding nature of phosphine donorwould discourage the orbital overlap between metal d-orbitals and theπ-system of the carbon-phosphorus (C^P) chelate, and confine theelectronic transitions occurred only at other chromophoric chelates. Asanticipated, bright phosphorescence across the whole visible spectrumcan be achieved through simple switch of the chromophoric ligands basedon a facile synthetic approach documented in literature.

Several carbon-phosphorus ancillary chelate with abbreviation (C^P)H isindicated below:

These carbon-phosphorus ligands (P^C)H, comprise of a tertiary phosphinefragment as well as an additional aromatic, heterocyclic or even alkenylC—H moiety, the latter can react with the transition-metal reagent tolost its hydrogen atom via direct C—H bond activation andcyclometalation, giving formation of the anionic carbon-phosphorus (P^C)chelate which is stabilized by formation of both metal-phosphine dativeinteraction and covalent metal-carbon bonding interaction. Moreover,after reacting with the employed metal reagent, the local arrangement ofcarbon-phosphorus (P^C) chelate formed a five-membered, planarmetallacycle, which could provide the highest stabilization to theresulting metal chelates. The relationship of five-membered metallacycleversus other less desirable, four-membered or six-membered (P^C)metallacycles is indicated below:

It is notable that if the polyaromatic or heterocyclic fragment such asnaphthalene, isoquinoline, indole and carbazole was employed to assemblethe carbon-phosphorus (C^P) chelate, due to the relatively smaller ππ*energy gap associated with these fragments, the chelate dominating thelowest energy excited states would be shifted from the previouslymentioned (C^N) or (N^N) chelates to the ancillary (P^C) chelate.Alternatively, if we selected the (C^N) and (N^N) chelates with a muchgreater degree of π-conjugation, c.f. that of 1-phenyl isoqunioline,1-phenyl quinazoline and 3-tert-butyl-5-(1-isoquinolinyl)pyrazole, thesechromophoric chelates would regain the dominance of emissive propertiesof the assembled Ir(III) metal complexes, giving a significantly betteremission efficiency in both fluid and solid states.

Moreover, a preferred synthesis of the emissive iridium (III) complexeswith the formula [(C^N)₂Ir(P^C)] comprises the following procedures:

The first step involved the thermal treatment of two equiv. of (N^C)Hwith IrCl₃.nH₂O in methoxyethanol to afford the dimer [(C^N)₂Ir(μ—Cl)]₂as intermediate. After then, reaction of this dimer with thecarbon-phosphorus chelate (C^P)H in high boiling decalin and in presenceof excess sodium acetate as HCl scavenger would initiate coordination of(C^P) chelate, followed by cyclometalation to afford the desiredheteroleptic complex of formula [(C^N)₂Ir(C^P)].

Alternatively, the emissive iridium (III) complexes with the formula[(N^N)Ir(P^C)₂] is best conducted employing the distinctive sequences:

In this reaction sequence, a distinctive iridium reagent IrCl₃(THT)₃ wasselected due to its increased solubility in high boiling hydrocarbonsolvent such as decalin. Thus, treatment of IrCl₃(THT)₃ with two equiv.of (C^P)H in presence of sodium acetate would give isolation of theintermediate [(C^P)₂Ir(OAc)] in high yields. This intermediate can befully characterized by spectroscopic means and, in one case, by singlecrystal X-ray diffraction study. Subsequent treatment of [(C^P)₂Ir(OAc)]with (N^N)H chelate produced the expected ligand exchange and formationof [(N^N)Ir(P^C)₂] in moderate yields. Alternatively, the reactionsequence can be simplified by skipping isolation of [(C^P)₂Ir(OAc)];thus, a one-pot procedure can be attained by further lowering the costfor its production.

Moreover, if the polyaromatic or heterocyclic fragment such asnaphthalene, isoquinoline, indole and carbazole was employed to assemblethe carbon-phosphorus (C^P) chelate, the resulting (C^P)H ligands areonly suitable for preparation of emissive metal complexes showing longerwavelength phosphorescence, typically in the region from orange to red.This is due to the smaller ππ* energy gap associated with thepolyaromatic and heterocyclic fragments that, in turn, would dominatethe lowest energy excited states of the tris-chelated metal complexes.If such situation occurred, (C^N) or (N^N) chelates should no longer beconsidered as the chromophoric ligands of the metal complexes.

Despite of this uncertainty in describing the exact characteristics ofexcited states, the resulting emissive metal complexes retain itcharge-neutral characteristics and greater volatility under reducedpressure or in vacuo at elevated temperature. These physical propertiesare essentially for the subsequent fabrication of OLEDs employing directthermal evaporation.

The present invention provides the phosphorescent metal complexes withcarbon-phosphorus ancillary chelate(s) and chromophoric ligand(s),synthetic method of preparing the same and phosphorescent organic lightemitting diode thereof for enhancing the quantum efficiency, syntheticyield of the iridium complexes and the luminous efficiency ofphosphorescent OLEDs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the x-ray structure of an Ir complex (2) synthesized inExample 1 according to the present invention.

FIG. 2 shows the x-ray structure of an Ir complex (3) synthesized inExample 1 according to the present invention.

FIG. 3 shows the UV/vis absorption and emission spectra of the complexes(1)-(4) in CH₂Cl₂ solution, which were prepared in Example 1 accordingto the present invention.

FIG. 4 shows the x-ray structure of an Ir complex (5) synthesized inExample 2 according to the present invention.

FIG. 5 shows the x-ray structure of an Ir complex (9) synthesized inExample 2 according to the present invention.

FIG. 6 shows the x-ray structure of an Ir complex (11) synthesized inExample 3 according to the present invention.

FIG. 7 shows the structure of the blue-emitting OLED made in Example 7of the present invention and the structures of the compounds usedtogether with an energy level diagram.

FIG. 8 show the performance of the OLED fabricated in Example 7 of thepresent invention, wherein (a) is EL spectrum; (b) CIE chromaticitycoordinate; (c) is I-V-L characteristics, and (d) is external quantumefficiency and power efficiency versus brightness thereof.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a phosphorescent tris-chelated transitionmetal complex comprising i) two identical carbon-nitrogen (C^N) ornitrogen-nitrogen (N^N) chelates being incorporated into a coordinationsphere thereof with a transition metal, and one carbon-phosphorus (C^P)chelate being incorporated into the coordination sphere; or ii) onecarbon-nitrogen (C^N) or nitrogen-nitrogen (N^N) chelate forming acoordination sphere thereof with a transition metal, and two identicalcarbon-phosphorus (C^P) chelates being incorporated into thecoordination sphere, wherein the transition metal is iridium, platinum,osmium or ruthenium, and iridium is preferable.

Preferably, the complex of the present invention is represented by thefollowing formulas Ia, Ib, Ic, Id or their stereo isomers:

wherein the C and N linked with an arch, or N and N linked with an archhave a formula of Ar¹-Ar², wherein Ar¹ is aromatic ring or aN-heterocyclic ring, and Ar² is N-heterocyclic ring, wherein C in theformulas Ia and Ib is a carbon atom contained in the aromatic ring ofAr¹ and N in the formulas Ia and Ib is a nitrogen atom contained in Ar²,N in the formulas Ic and Id is a nitrogen atom contained in theheterocyclic rings of Ar¹ and Ar²; the carbon-phosphorus (C^P) chelatesare presented by the P and C linked with an arch, and have a formula ofAr³—(C(R⁴R⁵))_(m)—P(Ar⁴Ar⁵), wherein m is 0, 1 or 2; Ar⁴ and Ar⁵independently are phenyl, functionalized phenyl, iso-propyl ortert-butyl; R⁴ and R⁵ independently are H or methyl; —Ar³ is

wherein R¹ and R² independently are alkyl, cyano, F or C_(n)F_(2n+1), nis an integer of 1-3; R³ is methyl, phenyl, alkyl, cyano, andfunctionalized aromatic group; and X is oxygen or sulfur.

Preferably, the carbon-phosphorus (C^P) chelates are

More preferably, Ar⁴ and Ar⁵ are both phenyl, and R¹ and R² are both F.

Preferably, the carbon-phosphorus (C^P) chelates are

More preferably, Ar⁴ and Ar⁵ are both phenyl, and R¹ and R² are both F.

Preferably, the carbon-phosphorus (C^P) chelates are

More preferably, Ar⁴ and Ar⁵ are both phenyl, and R¹ and R² are both F.

Preferably, the carbon-phosphorus (C^P) chelates are

More preferably, Ar⁴ and Ar⁵ are both phenyl. Alternatively, thenitrogen atom is relocated to other position except at the 8-position.

Preferably, the carbon-phosphorus (C^P) chelates are

More preferably, Ar⁴, Ar⁵ and R³ are all phenyl.

Preferably, the carbon-phosphorus (C^P) chelates are

More preferably, Ar⁴, Ar⁵ and R³ are all phenyl.

Preferably, the carbon-phosphorus (C^P) chelates are

More preferably, Ar⁴ and Ar⁵ are phenyl.

Preferably, the carbon-phosphorus (C^P) chelates are

More preferably, Ar⁴ and Ar⁵ are phenyl.

Preferably, the carbon-nitrogen (C^N) chelates are

wherein Bu^(t) is tert-butyl.

Preferably, the nitrogen-nitrogen (N^N) chelates are

wherein R is CF₃, tert-butyl, phenyl or functionalized phenyl group, andBu^(t) is tert-butyl.

The present invention also provides a phosphorescent organic lightemitting diode employing the phosphorescent tri-substituted metalchelate of the present invention as an emitting or emitter dopantmaterial.

As for the design of phosphorescent metal complexes, they comprises thetri-substituted chelating arrangement with one or even twocarbon-phosphorus (C^P) cyclometalated chelates into the coordinationsphere, together with at least one (C^N) or (N^N) chelate(s), for theadjustment of emission color. It is expected that the electronictransitions that produced the emission will be principally confined tothe chromophoric ligands that possess a slightly lowered energy gap(such as the energy gap for blue, green or red emission), due to theeffective blocking of the ligand-to-ligand energy transfer process, aswell as suppressing the unwanted thermal population to the higher lying,nonradiative metal-centered dd excited state. Thus, this moleculardesign would suppress the unwanted LLCT processes and give an enhancedemission quantum yield compared with all other emissive metal complexeswithout the carbon-phosphorus (C^P) cyclometalated chelate(s).

The present invention will be better understood through the followingexamples, where are for illustrative only and not for limiting the scopeof the present invention.

EXAMPLE 1 Synthesis of Ir(III) Complexes with Benzyldiphenylphosphine asCarbon-Phosphorus Chelate

General Experimental Procedures. All reactions were performed under anitrogen atmosphere using anhydrous solvents or solvents treated with anappropriate drying reagent. Mass spectra were obtained on a JEOL SX-102Ainstrument operating in electron impact (EI) mode or fast atombombardment (FAB) mode. ¹H and ¹⁹F NMR spectra were recorded on VarianMercury-400 or INOVA-500 instruments. Elemental analyses were conductedat the NSC Regional Instrumentation Center at National Chiao TungUniversity, Taiwan. X-Ray Diffraction Studies. Single crystal X-raydiffraction data were measured on a Bruker SMART Apex CCD diffractometerusing (Mo-K_(α)) radiation (λ=0.71073 Å). The data collection wasexecuted using the SMART program. Cell refinement and data reductionwere performed with the SAINT program. The structure was determinedusing the SHELXTL/PC program and refined using full-matrix leastsquares.

Spectral and dynamic measurement. Steady-state absorption and emissionspectra were recorded by a Hitachi (U-3310) spectrophotometer and anEdinburgh (FS920) fluorimeter, respectively. Emission quantum yieldswere measured at excitation wavelength λ_(ex)=350 nm in CH₂Cl₂ at roomtemperature. In this approach, Quinine sulfate with an emission yield ofΦ˜0.54±0.2 in 1.0 N sulfuric acid solution served as the standard tocalculate the emission quantum yield. Lifetime studies were performed byan Edinburgh FL 900 photon counting system with a hydrogen-filled or anitrogen lamp as the excitation source. Data were analyzed using anonlinear least squares procedure in combination with an iterativeconvolution method. The emission decays were analyzed by the sum ofexponential functions, which allows partial removal of the instrumenttime broadening and consequently renders a temporal resolution of ˜200ps.

Synthesis of [Ir(dfppy)₂(bdp)] (1): Benzyldiphenylphosphine (bdpH, 61mg, 0.22 mmol), [(dfppy)₂Ir(μ—Cl)]₂ (122 mg, 0.10 mmol) and sodiumacetate (82 mg, 1.00 mmol) were combined in degassed decalin (30 mL) andthe mixture was refluxed for 26 hour. After cooling to RT and removal ofsolvent, the residue was purified by silica gel column chromatographyusing a 1:3 mixture of ethyl acetate and hexane as the eluent. The paleyellow crystals were obtained by slow diffusion of hexane into a CH₂Cl₂solution at RT (70 mg, 0.08 mmol, 41%).

Spectral data of (1): MS (FAB, ¹⁹³Ir): m/z 848 (M+1)⁺; ¹H NMR (500 MHz,CDCl₃, 294K): δ 8.17 (d, J=9.5 Hz, 1H), 8.05 (d, J=8.5 Hz, 1H),7.55˜7.64 (m, 4H), 7.36˜7.40 (m, 3H), 7.28 (t, J=7.5 Hz, 2H), 6.93 (t,J=7.5 Hz, 1H), 7.37 (t, J=7.0 Hz, 1H), 6.72˜6.83 (m, 6H), 6.62˜6.66 (m,3H), 6.38˜6.43 (m, 1H), 6.27˜6.35 (m, 3H), 4.32 (dd, J=15.5, 8.0 Hz,1H), 4.21 (t, J=15.0, 1H). ¹⁹F-{¹H} NMR (376 MHz, CDCl₃, 294K): 6˜110.03(m, 2F), −110.23 (d, J=10.9 Hz, 1F), −110.28 (d, J=9.0 Hz, 1F). ³¹P-{¹H}NMR (202 MHz, CDCl₃, 294K): δ 13.34 (s, 1P).

Synthesis of [Ir(dfppy)₂(dfbdp)] (2):(2,4-difluorobenzyl)diphenylphosphine (dfbdpH, 69 mg, 0.22 mmol),[(dfppy)₂Ir(μ—Cl)]₂ (122 mg, 0.10 mmol) and sodium acetate (82 mg, 1.00mmol) were combined in degassed decalin (30 mL) and the mixture wasrefluxed for 26 hour. After cooling to RT and removal of solvent, theresidue was purified by silica gel column chromatography using a 1:1mixture of ethyl acetate and hexane as the eluent. The pale yellowcrystals were obtained by slow diffusion of hexane into a CH₂Cl₂solution at RT (82 mg, 0.09 mmol, 46%).

Spectral data of (2): MS (FAB, ¹⁹³Ir): m/z 885 (M⁺); ¹H NMR (500 MHz,CDCl₃, 294K): δ 8.21 (d, J=9.0 Hz, 1H), 8.06 (d, J=8.0 Hz, 1H),7.60˜7.65 (m, 3H), 7.51 (d, J=5.5 Hz, 1H), 7.42 (t, J=8.0 Hz, 1H), 7.38(d, J=7.5 Hz, 1H), 7.29 (t, J=7.0 Hz, 2H), 7.19˜7.21 (m, 1H), 6.91 (t,J=7.0 Hz, 1H), 6.85 (t, J=6.5 Hz, 1H), 6.78 (t, J=6.0 Hz, 3H), 6.56˜6.62(m, 3H), 6.33˜6.44 (m, 4H), 5.75 (d, J=9.0 Hz, 1H), 4.43 (t, J=15.5 Hz,1H), 3.94 (dd, J=17.0, 7.5 Hz, 1H). ¹⁹F-{¹H} NMR (376 MHz, CDCl₃, 294K):6˜109.25 (d, J=10.5 Hz, 1F), −109.75 (m, 4F), −115.50 (d, J=6.0 Hz, 1F).³¹P-{¹H} NMR (202 MHz, CDCl₃, 294K): δ 14.71(s, 1P).

Synthesis of [Ir(piq)₂(bdp)] (3): Benzyldiphenylphosphine (bdpH, 61 mg,0.22 mmol), [(piq)₂Ir(μ—Cl)]₂ (127 mg, 0.10 mmol) and sodium acetate (82mg, 1.00 mmol) were combined in degassed decalin (30 mL) and the mixturewas refluxed for 36 hour. After cooling to RT and removal of solvent,the residue was purified by silica gel column chromatography using a 1:3mixture of ethyl acetate and hexane as the eluent. The pale yellowcrystals were obtained by slow diffusion of hexane into a CH₂Cl₂solution at RT (87 mg, 0.07 mmol, 28%). [The abbreviation of piqHrepresents phenyl isoquinoline.]

Spectral data of (3): MS (FAB, ¹⁹³Ir): m/z 892 (M+1)⁺; ¹H NMR (500 MHz,CDCl₃, 294K): δ 8.79 (d, J=9.5 Hz, 1H), 8.76 (d, J=8.5 Hz, 1H), 8.12 (d,J=8.0 Hz, 1H), 8.08 (d, J=7.5 Hz, 1H), 7.79˜7.83 (m, 2H), 7.43 (d, J=6.0Hz, 1H), 7.66 (d, J=8.5 Hz, 1H), 7.54˜7.59 (m, 6H), 7.42 (dd, J=6.5, 2.5Hz, 1H), 7.32˜7.36 (m, 2H), 7.25˜7.27 (m, 2H), 7.13 (dd, J=7.0, 1.0 Hz,1H), 7.00 (d, J=6.5 Hz, 1H), 6.92˜6.96 (m, 2H), 6.89 (dd, J=7.0, 1.0 Hz,1H), 6.84 (t, J=7.5 Hz, 1H), 6.75 (td, J=7.5, 1.5 Hz, 1H), 6.62˜6.66 (m,2H), 6.51 (t, J=9.0 Hz, 2H), 6.38 (td, J=7.5, 1.5 Hz, 1H), 6.22˜6.26 (m,3H), 4.35 (dd, J=16.0, 9.0 Hz, 1H), 4.21 (dd, J=16.0, 13.0 Hz, 1H).³¹P-{¹H} NMR (202 MHz, CDCl₃, 294K): δ 15.12 (s, 1P).

Synthesis of [Ir(dfpbpy)₂(dfbdp)] (4): this sample was synthesized usingprocedures similar to those used in the synthesis of (2).

Spectral data of (4): MS (FAB, ¹⁹³Ir): m/z 885 (M+1)⁺; ¹H NMR (500 MHz,CDCl₃, 294K): δ 8.21 (s, 1H), 8.08 (s, 1H), 7.63 (t, J=8.5 Hz, 2H),7.36˜7.39 (m, 2H), 7.29 (t, J=6.5 Hz, 2H), 7.13 (dd, J=6.0, 3.5 Hz, 1H),6.90 (d, J=7.0 Hz, 1H), 6.87 (d, J=7.0 Hz, 1H), 6.75˜6.78 (m, 3H), 6.63(dd, J=7.5, 2.0 Hz, 1H), 6.57 (t, J=9.0 Hz, 2H), 6.33˜6.44 (m, 4H), 5.75(dd, J=5.5, 1.5 Hz, 1H), 4.41 (t, J=15.0 Hz, 1H), 3.92 (dd, J=16.0, 7.0Hz, 1H), 1.28 (s, 9H), 1.23 (s, 9H). ¹⁹F-{¹H} NMR (376 MHz, CDCl₃,294K): 6˜110.08 (m, 2F), −110.18 (d, J=9.4 Hz, 1F), −110.22 (d, J=10.2Hz, 1F), −110.52 (d, J=9.4 Hz, 1F), −115.80 (d, J=5.6 Hz, 1F). ³¹P-{¹H}NMR (202 MHz, CDCl₃, 294K): δ 14.83 (s, 1P).

The molecular structures of (2) and (3) are shown in FIGS. 1 and 2,respectively. Selected photophysical properties of complexes prepared inExample 1 were measured in degassed CH₂Cl₂ solution at room temperature,and are shown in Table 1.

TABLE 1 PL (in degassed CH₂Cl₂) Sample λ_(max) (nm) Q.Y. τ_(obs)(ns)k_(r) k_(nr) (1) 469 6.1 145 4.2 × 10⁵ 6.5 × 10⁶ (2) 457, 481 19 490 3.9× 10⁵ 1.7 × 10⁶ (3) 600 86 3440 2.5 × 10⁵ 4.1 × 10⁴ (4) 456, 480 67 14204.7 × 10⁵ 2.3 × 10⁵

FIG. 3 shows the UV/vis absorption and emission spectra of the complexesprepared in Example 1 in CH₂Cl₂ solution.

EXAMPLE 2 Synthesis of Ir(III) Complexes with Dual Carbon-PhosphorusChelates

Synthesis of [Ir(dfbdp)₂(OAc)] (5) IrCl₃(THT)₃ (110 mg, 0.20 mmol),(2,4-difluorobenzyl)diphenylphosphine (dfbdpH, 137 mg, 0.44 mmol), andsodium acetate (164 mg, 2.00 mmol) were combined in degassed decalin (15mL) and the mixture was refluxed for 3 hour. After cooling to RT andremoval of solvent, the residue was purified by silica gel columnchromatography using a 1:1 mixture of ethyl acetate and hexane as theeluent. The pale yellow crystals were obtained by slow diffusion ofhexane into a CH₂Cl₂ solution at RT (135 mg, 0.15 mmol, 76%).

Spectral data of (5): MS (FAB, ¹⁹³Ir): m/z 890 (M+1)⁺; ¹H NMR (500 MHz,CDCl₃, 294K): δ 7.58˜7.62 (m, 4H), 7.40˜7.44 (m, 2H), 7.29˜7.35 (m, 3H),7.23˜7.27 (m, 3H), 7.18˜7.22 (m, 2H), 7.06˜7.10 (m, 1H), 6.89˜6.93 (m,2H), 6.84 (td, J=8.0, 2.5 Hz, 1H), 6.53 (t, J=9.5 Hz, 1H), 6.42 (td,J=10.0, 2.0 Hz, 1H), 6.26 (dd, J=10.5, 1.0 Hz, 1H), 6.10˜6.13 (m, 2H),6.26 (dd, J=10.5, 1.0 Hz, 1H), 3.59 (dd, J=16.0, 9.5 Hz, 1H), 3.29˜3.37(m, 2H), 1.09 (ddd, J=16.0, 8.0, 2.0 Hz, 1H). ¹⁹F-{¹H} NMR (376 MHz,CDCl₃, 294K): 6˜108.99 (d, J=6.8 Hz, 1F), −109.18 (dd, J=9.8, 5.6 Hz,1F), −113.94 (t, J=6.0 Hz, 1F), −114.95 (d, J=6.0 Hz, 1F). ³¹P-{¹H} NMR(202 MHz, CDCl₃, 294K): δ 29.10˜29.21 (m, 1P), 11.63 (d, J=6.5 Hz, 1P).

The molecular structure of [Ir(dfbdp)₂(OAc)] (5) is shown in FIG. 4.

Synthesis of [Ir(dfbdp)₂(fbptz)] (6): IrCl₃(THT)₃ (110 mg, 0.20 mmol),(2,4-difluorobenzyl)diphenylphosphine (dfbdpH, 137 mg, 0.44 mmol), andsodium acetate (164 mg, 2.00 mmol) were combined in degassed decalin (15mL) and the mixture was refluxed for 2 hour. After cooling to RT,3-(trifluoromethyl)-5-(4-t-butylpyridyl) trazolate (fbptzH) (60 mg, 0.22mmol) was added and mixture was refluxed for 6 hour. After cooling to RTand removal of solvent, the residue was purified by silica gel columnchromatography using a 1:1 mixture of ethyl acetate and hexane as theeluent. The pale yellow crystals were obtained by slow diffusion ofhexane into a CH₂Cl₂ solution at RT (125 mg, 0.12 mmol, 58%).

Spectral data of (6): MS (FAB, ¹⁹³Ir): m/z 1085 (M+1)⁺; ¹H NMR (500 MHz,CDCl₃, 294K): δ 8.02 (d, J=2.0 Hz, 1H), 7.60 (d, J=6.0 Hz, 1H),7.42˜7.46 (m, 2H), 7.25˜7.34 (m, 5H), 7.20 (td, J=8.0, 2.0 Hz, 2H), 7.09(t, J=8.0 Hz, 1H), 7.02˜7.06 (m, 4H), 6.90 (td, J=7.5, 2.0 Hz, 2H), 6.84(dd, J=6.0, 2.5 Hz, 1H), 6.72 (t, J=8.5 Hz, 2H), 6.43˜6.50 (m, 3H),6.31˜6.36 (m, 2H), 5.57˜5.61 (m, 1H), 4.01 (dd, J=17.0, 11.0 Hz, 1H),3.84 (t, J=12.5 Hz, 1H), 3.77 (dd, J=16.5, 9.5 Hz, 1H), 2.66 (dd,J=16.5, 8.5 Hz, 1H), 1.33 (s, 9H). ¹⁹F-{¹H}NMR (376 MHz, CDCl₃, 294K):6˜63.37 (s, 3F), −109.39 (dd, J=9.8, 5.3 Hz, 1F), −110.61 (d, J=5.3 Hz,1F), −112.52 (t, J=6.4 Hz, 1F), −115.19 (d, J=5.6 Hz, 1F). ³¹P-{¹H} NMR(202 MHz, CDCl₃, 294K): δ 8.72 (d, J=10.1 Hz, 1P), 6.30˜6.44 (m, 1P).

Synthesis of [Ir(dfbdp)₂(fptz)] (7): IrCl₃(THT)₃ (110 mg, 0.20 mmol),(2,4-difluorobenzyl)diphenylphosphine (dfbdpH, 137 mg, 0.44 mmol), andsodium acetate (164 mg, 2 mmol) were combined in degassed decalin (15mL) and the mixture was refluxed for 2 hour. After cooling to RT,5-pyridyl-3-trifluoromethyl-1,2,4-triazole (fptzH) (47 mg, 0.22 mmol)was added and mixture was refluxed for 6 hour. After cooling to RT andremoval of solvent, the residue was purified by silica gel columnchromatography using a 1:1 mixture of ethyl acetate and hexane as theeluent. The pale yellow crystals were obtained by slow diffusion ofhexane into a CH₂Cl₂ solution at RT (102 mg, 0.10 mmol, 50%).

Spectral data of (7): MS (FAB, ¹⁹³Ir): m/z 1029 (M+1)⁺; ¹H NMR (500 MHz,CDCl₃, 294K): δ 7.83 (t, J=7.5 Hz, 2H), 7.79 (d, J=7.5 Hz, 1H), 7.55 (t,J=7.5 Hz, 1H), 7.48˜7.49 (m, 1H), 7.40˜7.44 (m, 2H), 7.36 (t, J=8.0 Hz,2H), 7.27 (t, J=7.5 Hz, 1H), 7.17˜7.21 (m, 4H), 6.87˜6.93 (m, 3H), 6.74(t, J=6.5 Hz, 3H), 6.60 (t, J=9.0 Hz, 2H), 6.54 (t, J=8.5 Hz, 1H), 6.49(dd, J=10.5, 2.0 Hz, 1H), 6.40 (td, J=9.0, 2.0 Hz, 1H), 6.20 (t, J=9.0Hz, 2H), 5.47˜5.50 (m, 1H), 3.86 (dd, J=15.5, 10.0 Hz, 1H), 3.62˜3.76(m, 2H), 1.87 (dd, J=17.0, 8.0 Hz, 1H). ¹⁹F-{¹H} NMR (376 MHz, CDCl₃,294K): 6˜63.75 (s, 3F), −107.24 (d, J=6.4 Hz, 1F), −109.16 (dd, J=9.0,5.6 Hz, 1F), −113.52 (d, J=6.4 Hz, 1F), −114.18 (t, J=6.4 Hz, 1F).³¹P-{¹H} NMR (202 MHz, CDCl₃, 294K): δ 9.12˜9.25 (m, 1P), 7.45 (d,J=10.3 Hz, 1P).

Synthesis of [Ir(dfbdp)₂(fppz)] (8): IrCl₃(THT)₃ (110 mg, 0.2 mmol),(2,4-difluorobenzyl)diphenylphosphine (dfbdpH, 137 mg, 0.44 mmol), andsodium acetate (164 mg, 2 mmol) were combined in degassed decalin (15mL) and the mixture was refluxed for 2 hour. After cooling to RT,5-pyridyl-3-trifluoromethyl-1H-pyrazole (fppzH) (47 mg, 0.22 mmol) wasadded and mixture was refluxed for 6 hour. After cooling to RT andremoval of solvent, the residue was purified by silica gel columnchromatography using a 1:1 mixture of ethyl acetate and hexane as theeluent. The pale yellow crystals were obtained by slow diffusion ofhexane into a CH₂Cl₂ solution at RT (92 mg, 0.09 mmol, 45%).

Spectral data of (8): MS (FAB, ¹⁹³Ir): m/z 1028 (M+1)⁺; ¹H NMR (500 MHz,CDCl₃, 294K): δ 7.84 (d, J=9.0 Hz, 1H), 7.82 (d, J=9.0 Hz, 1H), 7.42 (d,J=6.0 Hz, 1H), 7.39 (d, J=7.0 Hz, 1H), 7.27˜7.32 (m, 5H), 7.21 (t, J=7.5Hz, 1H), 7.16 (t, J=6.5 Hz, 2H), 7.08 (t, J=7.0 Hz, 2H), 6.86˜6.92 (m,3H), 6.81 (s, 1H), 6.73 (t, J=7.0 Hz, 2H), 6.66 (t, J=8.5 Hz, 2H), 6.52(t, J=6.5 Hz, 1H), 6.48˜6.49 (m, 2H), 6.39 (td, J=9.0, 2.0 Hz, 1H), 6.31(t, J=8.5 Hz, 2H), 5.64˜5.67 (m, 1H), 3.98 (dd, J=16.0, 11.0 Hz, 1H),3.75˜3.88 (m, 2H), 2.15 (dd, J=16.5, 6.0 Hz, 1H). ¹⁹F-{¹H} NMR (376 MHz,CDCl₃, 294K): 6˜60.51 (s, 3F), −108.13 (d, J=6.4 Hz, 1F), −109.92 (m,1F), −114.19 (d, J=6.0 Hz, 1F), −114.90 (m, 1F). ³¹P-{¹H} NMR (202 MHz,CDCl₃, 294K): δ 6.96 (m, 2P).

Synthesis of [Ir(bdp)₂(fppz)] (9): IrCl₃(THT)₃ (110 mg, 0.20 mmol),benzyl diphenylphosphine (bdpH, 122 mg, 0.44 mmol), and sodium acetate(164 mg, 2.00 mmol) were combined in degassed decalin (15 mL) and themixture was refluxed for 2 hour. After cooling to RT,5-pyridyl-3-trifluoromethyl-1H-pyrazole (fppzH) (47 mg, 0.22 mmol) wasadded and mixture was refluxed for 6 hour. After cooling to RT andremoval of solvent, the residue was purified by silica gel columnchromatography using a 1:1 mixture of ethyl acetate and hexane as theeluent. The pale yellow crystals were obtained by slow diffusion ofhexane into a CH₂Cl₂ solution at RT (92 mg, 0.10 mmol, 48

Spectral data of (9): MS (FAB, ¹⁹³Ir): m/z 956 (M+1)⁺; ¹H NMR (500 MHz,CDCl3, 294K): δ 7.89 (d, J=8.0 Hz, 1H), 7.87 (t, J=8.0 Hz, 1H), 7.50 (d,J=6.5 Hz, 1H), 7.43 (t, J=9.0 Hz, 2H), 7.33˜7.25 (m, 3H), 7.21 (d, J=7.5Hz, 1H), 7.15 (t, J=8.0 Hz, 3H), 7.11˜7.08 (m, 5H), 6.96 (t, J=7.5 Hz,1H), 6.85 (t, J=7.5 Hz, 1H), 6.82˜6.79 (m, 3H), 6.77 (s, 1H), 6.72 (t,J=7.5 Hz, 1H), 6.69˜6.66 (m, 3H), 6.61 (t, J=9.0 Hz, 2H), 6.43 (t, J=7.0Hz, 1H), 6.32 (t, J=8.5 Hz, 2H), 6.18 (t, J=6.0 Hz, 1H), 4.05 (dd,J=15.0, 11.0 Hz, 1H), 3.77 (dd, J=15.0, 11.0 Hz, 1H), 3.46 (dd, J=16.5,10.0 Hz, 1H), 2.17 (dd, J=16.5, 10.0 Hz, 1H). ¹⁹F-{¹H} NMR (470 MHz,CDCl₃, 294K): 6˜60.27 (s, 3F). ³¹P-{¹H} NMR (202 MHz, CDCl₃, 294K): δ6.29 (d, J=1.1 Hz, 1P), 6.18 (d, J=11. Hz, 1P).

The molecular structure of [Ir(bdp)₂(fppz)] (9) is shown in FIG. 5.

Synthesis of [Ir(bdp)₂(iqbtz)] (10): IrCl₃(THT)₃ (110 mg, 0.20 mmol),benzyldiphenyl phosphine (bdpH, 122 mg, 0.44 mmol), and sodium acetate(164 mg, 2.00 mmol) were combined in degassed decalin (15 mL) and themixture was refluxed for 2 hour. After cooling to RT,5-(1-isoquinolyl)-3-tert-butyl-1,2,4-triazole (iqbtzH) (56 mg, 0.22mmol) was added and mixture was refluxed for 6 hour. After cooling to RTand removal of solvent, the residue was purified by silica gel columnchromatography using a 1:1 mixture of ethyl acetate and hexane as theeluent. The pale yellow crystals were obtained by slow diffusion ofhexane into a CH₂Cl₂ solution at RT (99 mg, 0.10 mmol, 50%).

Spectral data of (10): MS (FAB, ¹⁹³Ir): m/z 995 (M+1)⁺; ¹H NMR (500 MHz,CDCl₃, 294K): δ 10.19 (d, J=7.5 Hz, 1H), 8.23 (d, J=7.5 Hz, 1H), 8.21(d, J=8.0 Hz, 1H), 7.70 (t, J=8.5 Hz, 2H), 7.57˜7.62 (m, 2H), 7.50˜7.51(m, 2H), 7.27˜7.34 (m, 2H), 7.21˜7.22 (m, 3H), 7.13˜7.19 (m, 3H), 7.09(d, J=7.0 Hz, 1H), 7.06 (d, J=8.0 Hz, 1H), 7.00 (t, J=7.5 Hz, 1H),6.75˜6.83 (m, 5H), 6.58 (t, J=7.5 Hz, 1H), 6.47 (t, J=8.5 Hz, 2H), 6.34(t, J=7.0 Hz, 2H), 6.24 (t, J=7.0 Hz, 1H), 6.14 (t, J=7.0 Hz, 1H), 6.09(t, J=8.5 Hz, 2H), 4.22 (dd, J=14.5, 11.0 Hz, 1H), 3.53 (dd, J=15.0,11.0 Hz, 1H), 3.36 (dd, J=17.0, 12.5 Hz, 1H), 1.89 (dd, J=16.5, 8.5 Hz,1H), 1.52 (s, 9H). ³¹P-{¹H} NMR (202 MHz, CDCl₃, 294K): δ 9.25 (d, J=9.3Hz, 1P), 8.74 (d, J=9.3 Hz, 1P).

The photophysical properties of compounds (6) to (10) are listed inTable 2.

TABLE 2 PL (in degassed CH₂Cl₂) Sample λ_(max) (nm) Q.Y. τ_(obs) k_(r)k_(nr) (6) 453 0.018 152.36 ns   1 × 10⁵ 5.5 × 10⁶ (7) 454 0.0005 2.95ns 1.7 × 10⁵ 3.4 × 10⁸ (8) 425, 457 0.0004 5.61 ns   7 × 10⁴ 1.7 × 10⁸(9) 460 0.003 3.05 ns 1.1 × 10⁶ 3.3 × 10⁸ (10)  599 1.0 35.5 μs 2.8 ×10⁴ —

EXAMPLE 3 Synthesis of Ir(III) Complexes with1-Isoquinolinyldiphenylphosphine as Carbon-Phosphorus Chelate

Synthesis of dpiq. 1-chloroisoquinoline (1.95 g, 12.00 mmol), copper(I)iodide (113 mg, 0.60 mmol), cesium carbonate (7.80 g, 24.00 mmol),diphenylphosphine (2.67 g, 14.40 mmol) and toluene (40 ml, it wasdistilled and stored under nitrogen) were in a Schlenk tube which wasunder pure and dry nitrogen. The reaction mixture was heated to 100° C.for 48 h. After this had cooled to room temperature, the solution wasremoved in vacuum. The residue was added H₂O (30 mL) and extracted withethyl acetate (40 mL×3). The organic extracts were dried over Na₂SO₄ andconcentrated in vacuum. The residue was loaded on a silica gel columnand eluted with 1/3 ethyl acetate/Hexane to give the product. The palegreen powders were crystallized from hot CH₂Cl₂ (2.36 g, 7.54 mmol,62%).

Spectral data of dpiq: MS (EI): m/z 313 (M⁺); ¹H NMR (500 MHz, CDCl₃,294K): δ 8.61 (dd, J=8.0, 4.5 Hz, 1H), 8.58 (d, J=5.6 Hz, 1H), 7.80 (d,J=8.0 Hz, 1H), 7.63 (t, J=8.0 Hz, 1H), 7.56 (d, J=5.6 Hz, 1H), 7.50 (t,J=8.0 Hz, 1H), 7.36˜7.44 (m, 4H), 7.28˜7.34 (m, 6H). ³¹P-{¹H} NMR (202MHz, CDCl₃, 294K): 6˜7.18 (s, 1P).

Synthesis of [Ir(dpiq)₂(fppz)] (11): IrCl₃(THT)₃ (165 mg, 0.30 mmol),1-(diphenylphosphino)isoquinoline (dpiq, 207 mg, 0.66 mmol) and sodiumacetate (246 mg, 3.00 mmol) were combined in decalin (20 mL). Thereaction mixture was heated to reflux for 2 h. After this had cooled toroom temperature, the mixture was added3-trifluoromethyl-5-(2-pyridyl)pyrazole (fppzH, 64 mg, 0.30 mmol) andthen heated to reflux for 9.5 h. After cooling to room temperature andremoval of solvent, the residue was loaded on a silica gel column andeluted with 2/3 ethyl acetate/hexane to give the product. The pale browncrystals were obtained from CH₂Cl₂ and Methanol (100 mg. 0.10 mmol,32%).

Spectral data of (11): MS (FAB, ¹⁹³Ir): m/z 1029 (M⁺); ¹H NMR (500 MHz,CDCl₃, 294K): δ 8.64 (t, J=8.0 Hz, 2H), 8.58 (d, J=5.5 Hz, 1H), 8.45 (d,J=5.5 Hz, 1H), 7.93 (d, J=8.0 Hz, 1H), 7.91 (d, J=8.0 Hz, 1H), 7.51 (d,J=8.0 Hz, 1H), 7.44˜7.49 (m, 2H), 7.32˜7.40 (m, 2H), 7.20˜7.31 (m, 4H),7.14˜7.20 (m, 2H), 7.12 (d, J=8.0 Hz, 1H), 7.04 (t, J=8.0 Hz, 2H),6.78˜6.88 (m, 2H), 6.72 (s, 1H), 6.56˜6.62 (m, 3H), 6.50 (t, J=6.0 Hz,1H), 6.41 (t, J=6.0 Hz, 1H), 6.28˜6.34 (m, 3H), 6.12 (t, J=9.0 Hz, 2H),5.82 (t, J=8.5 Hz, 2H). ¹⁹F-{¹H} NMR (470 MHz, CDCl₃, 294K): 6˜60.80 (s,3F). ³¹P-{¹H} NMR (202 MHz, CDCl₃, 294K): δ 16.17 (d, J=12.9 Hz, 1P),12.54 (d, J=12.9 Hz, 1P).

The molecular structure of [Ir(dpiq)₂(fppz)] (11) is shown in FIG. 6.

EXAMPLE 4 Synthesis of Ir(III) Complexes withNaphthalenyldiphenylphosphine as Carbon-Phosphorus Chelate

Synthesis of [Ir(ndp)₂(iqbtz)] (12): IrCl₃(THT)₃ (165 mg, 0.30 mmol),naphthalen-1-yldiphenylphosphine (ndp, 197 mg, 0.63 mmol) and sodiumacetate (246 mg, 3.00 mmol) were combined in decalin (20 mL). Thereaction mixture was heated to reflux for 2 h. After this had cooled toroom temperature, the mixture was added5-(1-isoquinolyl)-3-tert-butyl-1,2,4-triazaole (iqbtzH, 76 mg, 0.30mmol) and then heated to reflux for 5 h. After cooling to roomtemperature and removal of solvent, the residue was loaded on a silicagel column and eluted with 1/2 ethyl acetate/hexane to give the product.The orange crystals were obtained from CH₂Cl₂ and Hexane (196 mg. 0.194mmol, 64%).

Spectral data of (12): MS (FAB, ¹⁹³Ir): m/z 1067 (M+1)⁺; ¹H NMR (500MHz, CDCl₃, 294K): δ 10.10 (d, J=9.0 Hz, 1H), 8.24 (t, J=10.0 Hz, 2H),8.11 (d, J=8.0 Hz, 1H), 8.08 (d, J=8.0 Hz, 1H), 7.78˜7.84 (m, 2H),7.54˜7.62 (m, 3H), 7.46˜7.52 (m, 2H), 7.32˜7.40 (m, 3H), 7.29 (td,J=7.7, 2.0 Hz, 1H), 7.17˜7.24 (m, 3H), 7.15 (d, J=8.0 Hz, 1H), 7.07 (dd,J=10.0, 7.0 Hz, 1H), 6.96 (t, J=6.5 Hz, 3H), 6.80 (d, J=6.5 Hz, 1H),6.65 (t, J=8.0 Hz, 1H), 6.59 (t, J=8.0 Hz, 1H), 6.41 (d, J=7.0 Hz, 1H),6.18˜6.34 (m, 6H), 6.15 (t, J=8.5 Hz, 2H), 5.83 (t, J=8.5 Hz, 2H), 1.49(s, 9H). ³¹P-{¹H} NMR (202 MHz, CDCl₃, 294K): δ 16.04 (d, J=12.4 Hz,1P), 15.58 (d, J=12.4 Hz, 1P).

The photophysical properties of compounds (11) to (12) are listed inTable 3.

TABLE 3 PL (in degassed CH₂Cl₂) Sample λ_(max) (nm) Q.Y. τ_(obs) (ns)k_(r) k_(nr) (11) 576 0.22   2 × 10⁵ 1.1 × 10³ 3.9 × 10³ (12) 593 1.03.4 × 10⁵ 3.0 × 10³ 0

EXAMPLE 5 Synthesis of Ir(III) Complexes with9-(Diphenylphosphino)carbazole as Carbon-Phosphorus Chelate

Synthesis of dpc: A 2.5 M hexane solution of n-BuLi (4 mL, 10.0 mmol)was added dropwise to a stirred THF solution (50 mL) of carbazole (1.67g, 10.0 mmol) at −78° C. The reaction mixture was allowed to warm toroom temperature and stirred for 2 h. The white precipitate was isolatedby filtration, washed with hexane and redissolved in THF (70 mL).Chlorodiphenylphosphine (2.19 g, 9.9 mmol) was added dropwise to thesolution at 0° C. The reaction mixture was allowed to warm to roomtemperature and stirred for 12 h. The solution was filtered and thesolvent was evaporated under reduced pressure. The resulting white solidwas washed with hexane and dried under vacuum to give colorless powder(2.8 g, 8.0 mmol, 80%).

Spectral data of dpc: MS (EI): m/z 351 (M⁺); ¹H NMR (500 MHz, CDCl₃,294K): δ 8.05˜8.07 (m, 2H), 7.48˜7.52 (m, 2H), 7.38˜7.44 (m, 4H),7.30˜7.34 (m, 6H), 7.22˜7.28 (m, 4H). ³¹P-{¹H} NMR (202 MHz, CDCl₃,294K): δ 32.73 (s, 1P).

Synthesis of [Ir(dpc)(iqbtz)₂] (13): IrCl₃(THT)₃ (165 mg, 0.30 mmol),9-(diphenylphosphino)carbazole (dpc, 105 mg, 0.30 mmol) were combined indecalin (10 mL). The reaction mixture was heated to reflux for 2.5 h.After this had cooled to room temperature, the mixture was added sodiumacetate (246 mg, 3.00 mmol) and5-(1-isoquinolyl)-3-tert-butyl-1,2,4-triazaole (iqbtzH, 151 mg, 0.60mmol) and then heated to reflux for 6 h. After cooling to roomtemperature and removal of solvent, the residue was loaded on a silicagel column and eluted with 1/2 ethyl acetate/hexane to give the product.The orange crystals were obtained from CH₂Cl₂ and hexane (50 mg. 0.048mmol, 16%).

Spectral data of (13): MS (FAB, ¹⁹³Ir): m/z 1045 (M+1)⁺; ¹H NMR (500MHz, CDCl₃, 294K): δ 10.29 (d, J=8.0 Hz, 1H), 10.00 (d, J=9.0 Hz, 1H),8.02˜8.08 (m, 3H), 7.71˜7.80 (m, 3H), 7.60˜7.67 (m, 4H), 7.53 (d, J=6.5Hz, 1H), 7.40˜7.50 (m, 3H), 7.28 (t, J=7.5 Hz, 1H), 7.20˜7.25 (m, 1H),7.14˜7.18 (m, 2H), 7.06 (d, J=7.0 Hz, 1H), 7.00 (d, J=8.0 Hz, 1H), 6.82(t, J=8.0 Hz, 1H), 6.38˜6.53 (m, 5H), 6.03 (d, J=7.0 Hz, 1H), 1.28 (s,9H), 1.05 (s, 9H). ³¹P-{¹H}NMR (202 MHz, CDCl₃, 294K): δ 44.77 (s, 1P).

Synthesis of [Ir(dpc)₂(iqbtz)] (14): IrCl₃(THT)₃ (165 mg, 0.30 mmol),9-(diphenylphosphino)carbazole (dpc, 210 mg, 0.60 mmol) and sodiumacetate (246 mg, 3.00 mmol) were combined in decalin (10 mL). Thereaction mixture was heated to reflux for 2.5 h. After this had cooledto room temperature, the mixture was added5-(1-isoquinolyl)-3-tert-butyl-1,2,4-triazaole (iqbtzH, 76 mg, 0.30mmol) and then heated to reflux for 12 h. After cooling to roomtemperature and removal of solvent, the residue was loaded on a silicagel column and eluted with 1/2 ethyl acetate/hexane to give the product.The orange crystals were obtained from CH₂Cl₂ and MeOH (131 mg. 0.11mmol, 38%).

Spectral data of (14): MS (FAB, ¹⁹³Ir): m/z 1044 (M⁺); ¹H NMR (500 MHz,CDCl₃, 294K): δ 10.03 (d, J=8.0 Hz, 1H), 8.04 (t, J=10.0 Hz, 2H), 7.96(d, J=8.0 Hz, 1H), 7.92 (d, J=8.0 Hz, 1H), 7.82 (t, J=10.0 Hz, 2H),7.54˜7.64 (m, 4H), 7.39˜7.42 (m, 2H), 7.35 (d, J=7.5 Hz, 1H), 7.29 (d,J=7.5 Hz, 1H), 7.19˜7.25 (m, 3H), 7.08˜7.13 (m, 2H), 7.03˜7.07 (m, 3H),6.95 (d, J=6.0 Hz, 1H), 6.87 (t, J=8.0 Hz, 1H), 6.75˜6.82 (m, 2H),6.50˜6.60 (m, 3H), 6.36˜6.43 (m, 3H), 6.28˜6.35 (m, 4H), 5.93˜6.00 (m,3H), 1.48 (s, 9H). ³¹P-{¹H} NMR (202 MHz, CDCl₃, 294K): δ 48.40 (d,J=4.7 Hz, 1P), 46.42 (d, J=4.7 Hz, 1P).

EXAMPLE 6 Ir(III) Complexes with4-(Diphenylphosphino)-1-phenyl-1H-indole as Carbon-Phosphorus Chelate

Synthesis of [Ir(dpppi)₂(fppz)] (15): IrCl₃(THT)₃ (165 mg, 0.30 mmol),4-(diphenylphosphino)-1-phenyl-1H-indole (dpppi, 250 mg, 0.74 mmol) andsodium acetate (246 mg, 3.00 mmol) were combined in decalin (10 mL). Thereaction mixture was heated to reflux for 3 h. After this had cooled toroom temperature, the mixture was added3-trifluoromethyl-5-(2-pyridyl)pyrazole (fppzH, 64 mg, 0.30 mmol) andthen heated to reflux for 24 h. After cooling to room temperature andremoval of solvent, the residue was loaded on a silica gel column andeluted with 1/3 ethyl acetate/hexane to give the product. The orangecrystals were obtained from CH₂Cl₂ and MeOH (22 mg. 0.021 mmol, 7%).

Spectra data of (15): MS (FAB, ¹⁹³Ir): m/z 1058 (M⁺); ¹H NMR (CDCl₃, 400MHz, 294K): δ 8.27 (d, J=7.6 Hz, 1H), 8.24 (d, J=7.6 Hz, 1H), 7.94˜7.99(m, 3H), 7.52 (dd, J=8.0, 2.8 Hz, 1H), 7.46˜7.49 (m, 1H), 7.33˜7.40 (m,8H), 7.22˜7.28 (m, 5H), 7.08˜7.20 (m, 6H), 7.03 (td, J=7.7, 1.6 Hz, 2H),6.69˜6.86 (m, 2H), 6.71 (t, J=6.8 Hz, 1H), 6.65 (s, 1H), 6.62 (td,J=7.6, 2.0 Hz, 2H), 6.56 (t, J=6.6 Hz, 1H), 6.47˜6.51 (m, 2H), 6.42 (td,J=7.6, 2.4 Hz, 2H), 6.07 (m, 2H), 5.94 (s, 1H), 5.89 (s, 1H). ¹⁹F-{¹H}NMR (CDCl₃, 470 MHz, 294K): δ −60.56 (s, 3F). ³¹P-{¹H} NMR (CDCl₃, 202MHz, 294K): δ 21.88 (d, J=11.1 Hz, 1P), 10.82 (d, J=11.1 Hz, 1P).

EXAMPLE 7 General Method of Producing OLEDs

Synthesized compounds according to this disclosed specification weresubject to purification by temperature-gradient sublimation in highvacuum before use in subsequent device studies. OLEDs were fabricated onthe ITO-coated glass substrates with multiple organic layers sandwichedbetween the transparent bottom indium-tin-oxide (ITO) anode and the topmetal cathode. The material layers were deposited by vacuum evaporationin a vacuum chamber with a base pressure of <10⁻⁶ torr. The depositionsystem permits the fabrication of the complete device structure in asingle vacuum pump-down without breaking vacuum. The deposition rate oforganic layers was kept at ˜0.2 nm/s. The active area of the device is2×2 mm², as defined by the shadow mask for cathode deposition.

A device structure and materials used were ITO/NPD (30 nm)/TCTA (20nm)/CzSi (3 nm)/CzSi: (4) 7.0 wt. % (35 nm)/UGH2: (4) 7.0 wt. % (3nm)/UGH2 (2 nm)/BCP (50 nm)/Cs₂CO₃ (2 nm)/Ag. Theα-naphthylphenylbiphenyl diamine (α-NPD) and4,4′,4″-tri(N-carbazolyl)triphenylamine (TCTA) were used as thehole-transport layer (HTL). The thin CzSi (30 Å) was served both as thehole-transport layer and as the buffer layer for blocking thehigh-energy triplet excitons (on (4)) from migrating to TCTA (with alower triplet energy). Double emitting layers (CzSi and UGH2 doped with7.0 wt. % of (4)) were used to achieve better balance between hole andelectron injection/transport and thus to move the exciton formation zoneaway from the quenching interfaces with carrier-transport layers, takingadvantage of the hole-transport nature of CzSi and theelectron-transport nature of UGH2. The thin UGH2 (20 Å) was served bothas the electron-transport/hole-blocking layer and as the buffer layerfor blocking the high-energy triplet excitons from migrating to BCP(with a lower triplet energy). Finally,2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was used as theelectron-transport layer, and Ag or Cs₂CO₃ were used as theelectron-injection layer.

FIG. 7 shows the structure of the blue-emitting OLEDs made in thisexample and the structures of the compounds used together with an energylevel diagram.

The current-voltage-brightness (I-V-L) characterization of thelight-emitting devices was performed with a source-measurement unit(SMU) and a calibrated Si photodiode with Photo Research PR650. ELspectra of devices were collected by a calibrated CCD spectragraph. Theperformance of the OLEDs fabricated in this example are shown FIG. 8 andTable 4.

TABLE 4 External Luminance Power CIE coordinate Quantum EfficiencyEfficiency (x, y) Sample Efficiency (%) (cd/A) (lm/W) (@ 100 cd/m²) (4)Peak 7.86 11.55 6.8 (0.155, 0.186) 100 7.11 10.46 3.6 cd/m²

1. A phosphorescent tris-chelated transition metal complex comprising i)two identical carbon-nitrogen (C^N) or nitrogen-nitrogen (N^N) chelatesbeing incorporated into a coordination sphere thereof with a transitionmetal, and one carbon-phosphorus (C^P) chelate being incorporated intothe coordination sphere; wherein the transition metal is iridium.
 2. Thecomplex of claim 1, wherein the complex is represented by the followingformulas Ia, Ic, or their stereo isomers:

wherein the C and N linked with an arch, or N and N linked with an archhave a formula of Ar¹-Ar², wherein Ar¹ is aromatic ring or aN-heterocyclic ring, and Ar² is N-heterocyclic ring, wherein C in theformula Ia is a carbon atom contained in the aromatic ring of Ar¹ and Nin the formulas Ia is a nitrogen atom contained in Ar², N in the formulaIc is a nitrogen atom contained in the heterocyclic rings of Ar₁ andAr²; the carbon-phosphorus (C^P) chelates are presented by the P and Clinked with an arch, and have a formula of Ar³—(C(R⁴R⁵))_(m)—P(Ar⁴Ar⁵),wherein m is 0, 1 or 2; Ar⁴ and Ar⁵ independently are phenyl,functionalized phenyl, iso-propyl or tert-butyl; R⁴ and R⁵ independentlyare H or methyl; —Ar³ is

wherein R¹ and R² independently are alkyl, cyano, F or C_(n)F_(2n+1), nis an integer of 1-3; R³ is methyl, phenyl, alkyl, cyano, andfunctionalized aromatic group; and X is oxygen or sulfur.
 3. The complexof claim 2, wherein the carbon-phosphorus (C^P) chelates are


4. The complex of claim 3, wherein Ar⁴ and Ar^(s) are both phenyl, andR¹ and R² are both F.
 5. The complex of claim 2, wherein thecarbon-phosphorus (C^P) chelates are


6. The complex of claim 5, wherein Ar⁴ and Ar⁵ are both phenyl, and R¹and R² are both F.
 7. The complex of claim 2, wherein thecarbon-phosphorus (C^P) chelates are


8. The complex of claim 7, wherein Ar⁴ and Ar⁵ are both phenyl, and R¹and R² are both F.
 9. The complex of claim 2, wherein thecarbon-phosphorus (C^P) chelates are


10. The complex of claim 9, wherein Ar⁴ and Ar⁵ are both phenyl.
 11. Thecomplex of claim 9, wherein the nitrogen atom is relocated to otherposition except at the 8-position.
 12. The complex of claim 2, whereinthe carbon-phosphorus (C^P) chelates are


13. The complex of claim 12, wherein Ar⁴, Ar⁵ and R³ are all phenyl. 14.The complex of claim 2, wherein the carbon-phosphorus (C^P) chelates are


15. The complex of claim 14, wherein Ar⁴, Ar⁵ and R³ are all phenyl. 16.The complex of claim 2, wherein the carbon-phosphorus (C^P) chelates are


17. The complex of claim 16, wherein Ar⁴ and Ar⁵ are phenyl.
 18. Thecomplex of claim 2, wherein the carbon-phosphorus (C^P) chelates are


19. The complex of claim 18, wherein Ar⁴ and Ar⁵ are phenyl.
 20. Thecomplex of claim 2, wherein the carbon-nitrogen (C^N) chelates are

wherein Bu^(t) is tert-butyl.
 21. The complex of claim 2, wherein thenitrogen-nitrogen (N^N) chelates are

wherein R is CF₃, tert-butyl, phenyl or functionalized phenyl group, andBu^(t) is tert-butyl.
 22. A phosphorescent tris-chelated transitionmetal complex comprising i) two identical carbon-nitrogen (C^N) ornitrogen-nitrogen (N^N) chelates being incorporated into a coordinationsphere thereof with a transition metal, and one carbon-phosphorus (C^P)chelate being incorporated into the coordination sphere; wherein thetransition metal is platinum.
 23. A phosphorescent tris-chelatedtransition metal complex comprising i) two identical carbon-nitrogen(C^N) or nitrogen-nitrogen (N^N) chelates being incorporated into acoordination sphere thereof with a transition metal, and onecarbon-phosphorus (C^P) chelate being incorporated into the coordinationsphere; wherein the transition metal is osmium.